I have just changed the battery on the old girl(AU Series 1 Build date March 2000) and now when you drive the car all is fine till you want to stop then the engine wants to stall. I have checked all connections and relays but can't find any problems.
Had a simular problem a wile back which turned out to be a BrakeBooster replacement but this time the problem seems to be much worse. I got the car home and tried a few things like sitting with the car in Drive no problem put your foot on the brake pedle then the car tries to stall, then it seems to fix it self but if you try to drive the car it stalls.
Please any help on this matter will help as l am stuck at home till l can fix this problem.

You may just have to get your idler tweaked up a bit more. if you start it and just sit there does it sound or feel like its struggling to keep started? You can have someone adjust your idle which may help your problem. I had similar problems before and I got my idler adjusted and havent had problems since. If its not your problem then im not sure what would cause the problem sorry.
Good Luck!!!

I do find it a bit weird when you said you just sit there in drive and everything is ok but when you hit the brake it acts up hmmmm (shaking head).

Check the hose that goes from the brake booster. Make sure it is in good condition with no kinks or damage in it and make sure it is connected properly.